A valve is a device that regulates the flow of a fluid by opening, closing, or partially obstructing various passageways. Some valves are operated manually, while others are configured to operate automatically in response to changing conditions with the subject fluid passage. Valves may be used in complex automatic control systems and may require an actuator, such as a solenoid, to actuate a particular valve based on an external input.
Valves are employed in a multitude of industries and are often used to regulate flows of various fluids in motor vehicles. In vehicle internal combustion engines, valves are commonly employed for regulating flows of coolant and oil. For example, solenoid controlled valves may be used to regulate pressurized oil for switching latch pins in hydraulic valve lifters, lash adjusters, etc., in engine valve train systems.